Bit and block assembly

ABSTRACT

THE ASSEMBLY INCLUDES A BIT HAVING A BEARING FACE AT THE BUTT END AND A CUTTING HEAD AT THE OTHER END. A BASE BLOCK IS PROVIDED WHICH INCLUDES A SUPPORT PORTION HAVING A HOLE RECEIVING THE SHANK OF THE BIT AND A BEARING FACE WHICH IS SPACED FROM THE SUPPORT PORTION TO PROVIDE A TRANSVERSE OPENING COMPLETELY EXPOSING THE SHANK OF THE BIT AT TE BEARING END. THE TRANSVERSE OPENING FACILITATES ACCESS TO THE BUTT END OF THE BIT AND ASSISTS DISPERSAL OF COLLECTED DEBRIS. THE BEARING PORTION OF THE BASE BLOCK INCLUDES A REPLACEABLE PAD WHICH IS REMOVABLE FROM THE TRANSVERSE OPENING WITHOUT THE NECESSITY TO WITHDRAW THE BIT FROM THE SUPPORT COMPLETELY. A LOCK RING FRICTIONALLY ENGAGING THE REDUCED PORTION OF THE BIT INSURES AGAINST INADVERTENT WITHDRAWAL OF THE BIT FROM THE HOLE IN THE SUPPORT PORTION. THE BASE BLOCK IS SUSCEPTIBLE TO MODIFICATION TO ACCEPT A REVERSIBLE TYPE OF BIT. FURTHER, THE REPLACEABLE PAD MAY BE PROVIDED WITH A RESILIENT PLUG THAT MOVES THE BIT LINGITUDINALLY AND KEEPS THE BIT FREE FOR ROTATION. THE TRANSVERSE OPENING MAY BE PROVIDED BY A CIRCULAR HOLE.

"Jain l2,-V 4i971 -G.V 'w. ELDERS f -3,554,605

BIT Nb BLOCK ASSEMBLY Filed Demfzojle? 2 sheets-sheets United States Patent O 3,554,605 BIT AND BLOCK ASSEMBLY. Gerald W. Elders, Hillcrest, Christopher, Ill. 62822 Filed Dec. 20, 1967, Ser. No. 692,078 Int. 'Cl. E21c 35/18 U.S. Cl. 299-86 2 Claims ABSTRACT OF THE DISCLOSURE The assembly includes a bit having a bearing face at the butt end and -a cutting head at the other end. A base block is provided which includes a support portion having a hole receiving the shank of the bit and a bearing face which is spaced from the support portion to provide a transverse opening completely exposing the shank of the bit at the bearing end. The transverse opening facilitates access to the butt end of the bit and assists dispersal of collected debris. The bearing portion of the base block includes a replaceable pad which is removable from the transverse oepning without the necessity to withdraw the bit from the support completely. A lock ring frictionally engaging the reduced portion of the bit insures against inadvertent withdrawal of the bit from. the hole in the support portion. The base block is susceptible to modification to accept a reversible type of bit. Further, the replaceable pad may be provided with a resilient plug that moves the bit longitudinally and keeps the bit free for rotation. The transverse opening may be provided by a circular hole.

BACKGROUND OF TH'E INVENTION This invention relates generally to improvements in a bit and mounting assembly and' more particularly to an improved method of mounting such a bit to facilitate access to the butt end of the bit in the mounted condition.

Cutting bits, which are used in the ore and coal industry, necessarily operate in conditions under which they are subject to a high degree of abrasive wear. Understandably, the parts which take most of the wear require replacement at fairly frequent intervals. In consequence of this, great economic savings are possible with any improvement which increases the hard-wearing qualities of the materials used in the cutting process or increases the eiciency with which such parts may be replaced. yIn many cases, a time stoppage and the concomitant expenditure of work hours for the replacement of parts results in a financial loss much greater than the cost of the replaced parts themselves.

Applicants assembly, by exposing the area of the bit in the vicinity of the bearing between the bit and the mounting, permits direct and easy access to that area. This greatly reduces the time ta-ken to replace the bit.

Further, applicant has provided a replaceable bearing pad which may be removed without extracting the bit totally from its mounting. Considerable advantages accrue from this, because of the constricted nature of the working environment which is often experienced in this particular industry.

Frequently, and particularly in the case of those bits in which the operation depends on the rotation of the bit, the bearing area becomes clogged with debris, thereby effectively reducing or even destroying the efficiency of the moving part. Applicants assembly precludes the collection of such debris.

Generally speaking, blind sockets have been used in the prior art. Such sockets frequently become clogged and this, of course, impairs the working eiciency of the parts.

Patented Jan. 12, 1971 SUMMARY OF THE INVENTION The assembly includes a bit having an elongate shank provided with a bearing face at the butt end and a cutting head at the other end.

A base block provides a support means receiving the shank of the bit and a bearing means operatively engaging the butt end of the bit.

The bearing means is disposed in spaced relation from the support means longitudinally of the shank, and partially defines a transverse opening exposing the entire periphery of a portion of the shank at the butt end of the shank. The transverse opening facilitates access to the butt end and facilitates dispersion of debris.

Lock means, disposed in the transverse opening, intercepts the path of the shank to inhibit outward movement of the shank from the bearing means. The transverse opening is partially dened by a wall portion, which interconnects the bearing means and the support means and spaced from the exposed portion of the shank, the wall portion sloping away from the exposed shank transversely of said shank.

The bearing means includes a replaceable bearing pad selectively removable from the opening and a retaining means holds the bearing pad in position to insure transverse alignment of the bearing pad `with the bearing face Aat the butt end of the shank, yet allowing selective movement of the bearing pad longitudinal of the shank.

The support means includes an abutment, which partially deiines the opening, and the lock means cooperates -With the abutment to preclude outward movement of the butt end of the shank from the bearing means.

The replaceable pad includes a depending plug and the retaining means includes a socket slidably receiving the plug to hold the bearing pad in position, the plug being suiciently short to allow selective removal of the pad from the opening.

The bit is tapered at each end to provide a reversible bit. One of said tapered ends provides the butt end of the bearing face and the other of said ends provides the cutting head the bearing means includes a tapered socket receiving and engaging the bearing face at the butt end.

Resilient means operatively act on the bearing pad to engage the shank butt end to keep the shank free.

The transverse opening is substantially circular and the support means includes an elongate hole operatively receiving the shank and communicating with the substantially circular opening.

The substantially circular opening has a diameter greater than the diameter of the shank and the exposed portion of the shank is less than the maximum supported length of the shank to insure support when the shank is Withdrawn from the opening.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a side elevational View of a bit and mounting assembly;

FIG. 2 is a fragmentary sectional view taken on line 2-2 of FIG. l illustrating the bit lock;

FIG. 3 is a fragmentary elevational view taken on line 3--3 of FIG. 1 illustrating the bearing;

FIG. 4 is a fragmentary side elevational view of the bit and mounting, partly in cross section illustrating the replaceable bearing pad;

FIG. 5 is a side elevational view partly in cross section of the bit and mounting, illustrating a reversible bit;

FIG. 6 is a fragmentary view of a bit and mounting illustrating a resiliently cushioned bearing pad; and

FIG. 7 is a fragmentary view of a bit and mounting in which the mounting block includes a circular access hole transverse to the bit.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now by characters of reference to the drawings, and rst to the embodiments of FIGS. 1 through 3, it will be understood that the bit and mounting assembly includes a bit 10 and a base block 11.

The base block 11 includes a support portion 12 constituting a support means and including an elongate hole 13 into which the shank 14 of the bit is slidably received.

A bearing portion 15 constituting a bearing means operatively engages a bearing face 16 at the butt end 17 of the bit 10.

The bearing portion 15 is disposed in spaced relation from the support means, in a direction longitudinally of the shank, to provide a transverse opening 20 which exposes the entire periphery of the end portion of the shank. The transverse opening 20 is partially defined by an abutment face 21 on the bearing portion 15, and an abutment face 22 provided on the support portion 12. A curved wall portion 23 which slopes away from the exposed portion of the shank 14 interconnects the bearing portion 15 and the support portion 12 of the base block 11. FIGS. 2 and 3 clearly illustrate this structural arrangement of abutments 21 and 22 and the curved wall 23, which together serve to deiine the transverse opening 20.

The transverse opening 20 facilitates access to the butt end of the bearing and allows dispersal of debris in the general bearing area.

In mining operations of the kind which utilize the bit and mounting described, a serious problem exists with regard to the collection of dust and other debris resulting from the recovery of mineral ores and coal. In particular the dust tends to clog the parts of the bit and mounting and choke the bit bearing area to such an extent that the bits tend to become bound in position. Thus the operation of rotating bits, in particular, is severely hindered. The transverse opening 20 provides a free area all around the periphery of the exposed portion of the shank 14 and, in addition, the sloping away of the wall 23, which is enhanced by providing a groove 24, inhibit the collection of such debris and thereby precludes extensive build-up.

In the embodiment of the bit shown in FIG. 1, the shank 14 includes a reduced portion 25. This reduced portion 25 provides, in a sense, a wide circular groove which is almost the width of the opening and which may be fitted with a lock ring 26. The lock ring 26 is relatively narrow and frictionally engages the reduced portion 25 of the shank 14. It also engages the abutment 22 to inhibit outward movement of the shank 14 from the bearing portion 15.

It will be clear that the lock ring 26, while it is in position, provides a positive stop means precluding total withdrawal of the bit 10 from the transverse opening 20. This is because the lock ring 26 will engage the rim 27 of the bit 10 when the outward movement of the bit 10 is suiiiciently great for engagement to take place. The lock ring 26 intercepts the path of the -butt end of the bit 10 to preclude total withdrawal of the bit.

The provision of a locking arrangement such as that described, while it inhibits outward movement of the bit 10, does not inhibit rotation of the bit 10 in those situations in which a rotating bit is used.

FIG. 4 illustrates an embodiment of the bit and mounting assembly in which a replaceable bearing pad 30 is provided as part of the bearing portion 15. In other respects, the embodiment disclosed in FIG. 4 is substantially the same as that disclosed in FIG. 1. The same representative numerals designate substantially similar parts.

The pad 30 includes a bearing face 32 which substantially performs the same function as the abutment 21 in the embodiment disclosed in FIG. 1. The shape of the pad 30 may conform substantially to the shape of abutment 21 illustrated in FIG. 3.

The pad 30 also includes a stem 34 constituting a plug. The bearing portion 15 is provided with an elongate hole 35, which constitutes a socket receiving the stem. The stem provides a retaining means holding the bearing pad in position to insure transverse alignment of the bearing pad 30 with the bearing face 16 at the butt end 17 of the shank 14. The stem 35 is provided with a split pin 36 or other locking means at its outer end.

The length of the stem 34 is such as to permit selective removal of the replaceable bearing pad from the opening 20 without the necessity of total removal of the bit 10 from the support portion 12. Thus, by applying an outward force to the cutting head end 18 of the bit 10, the bit 10 may be partially withdrawn to the extent that the rim 17 engages the lock spring 26. If the stem 34 i's made no longer than the width of the opening less 'the combined thicknesses of the lock spring 26 and the butt end 17, the bearing pad 30 may be withdrawn from the elongate hole 35 and selectively removed from the transverse opening. This operation may be accomplished without `the need to withdraw the bit 10 from its support 12.

It will be understood that any withdrawal of the bit 10 takes place against the frictonal resistance afforded by the lock spring 26. When a replacement bearing pad has been installed, the bit 10 may be moved inwardly by pushing on the cutting head 18, the force being applied against the frictional resistance of the spring 26. The lock spring 26 may be digitally held in place against abutment 22 during this operation.

In FIG. 5, another embodiment is illustrated. Again, like representative numerals for like parts of the bit and mounting assembly are provided for convenience. The essential difference between this yspecies and the species disclosed in FIG. 4 is that the mounting is adapted for use with a reversible bit 40. Each end of the bit 40 includes a tapered portion 4.1 which serves either as a butting head, to which the cutting head carbide point 42 is attached, or as a butt end. Each tapered end portion is provided with a transverse flat face 45 which includes attaching means for the carbide point 42. The bearing pad 30 includes a conforming socket portion 44 into which the taper butt end 41 is received, the conical side Of the socket 44 providing a bearing face engaging the conforming peripheral bearing surface at the butt end of the tapered portion 41.

A narrow groove 43 is provided at each end of the shank 40, the groove 43 having a compatible configuration receiving the lock ring 26.

As opposed to the embodiment disclosed in FIG. 4, the lock ring 26 must normally be removed before the bit `40 can be withdrawn a sufficient distance outwardly to enable the replaceable pad 30 to be selectively removed from the opening 20.

The length of the elongate hole 13 is substantially greater than the length of the exposed portion of the shank 14 in order to insure that the shank will be rmly supported even in the condition when the head is withdrawn outwardly from the opening.

The embodiment disclosed in FIG. 6 is, as to the bit 10 and the locking means provided by the lock spring 26, substantially the same as the embodiment of FIG. 4. However, the bearing pad 30 differs in that it is provided with resilient means to move the bit 10 longitudinally and keep the bit 10 free in the block for rotation. This resilient means is provided a resilient plug in the elongate hole 35 and utilizes a set screw 51 to hold the resilient plug 50 in position.

In order to limit the movement of the pad 30 in a direction longitudinal of the shank, a slotted hole 52 is provided in the stem 34 of the bearing pad 30. A pin 53 provides a retaining means insuring that the movement of the pad 30 will be limited as required. The pin 53 will move longitudinally relative to the hole 52 to permit movement of the pad 30 and will engage the end margins defining the slotted hole 52 to limit such pad movement.

It will be clear that the pin 53, which slidably inserted in and carried by is the bearing portion 15, must be removed from the slotted hole 52 before the replaceable bearing pad 30 may, in turn, be removed from the opening 20.

FIG. 7 discloses an embodiment of the bit and mount- 'ing assembly in which the transverse opening is provided by a substantially circular hole 60. The elongate hole 13 into which the bit 10 is slidably received communicates with the circular hole 60. Diametrically opposite to the elongate hole 13 and on the same axis with it, a circular recess 61 provides a socket which receives ithe bearing pad 30. It will be clear that the manufacture of this particular embodiment is facilitated considerably by providing a recess `61 which is substantially the same diameter as the elongate hole 13. In this way, the -butt end 17 of the bt 10 may also be slidably received within the recss 61. Of course, this is not a mandatory requirement.

The locking action of the lock spring 26 is substantially the same in the embodiment of FIG. 7 as has been described with reference to the embodiment of FIG. 4.

There are some differences, however. For example, it will be noticed that no flat abutment such as that denoted by numeral 22 in FIG. 4 is provided. Rather, the lock 26 engages the side wall of the circular hole 60, the

effect, however, is Isubstantially the same. The hole 60 is substantially larger in diameter than the diameter of the exposed portion of the shank 14 to permit al1-around access to the exposed portion and in particular to the bearing area.

It is thought that the functional advantages of this bit and mounting assembly become fully apparent from the foregoing description of parts of the various embodiments.

It will be understood that the description of the removal of the bearing head' 30 made with regard to the embodiment of FIG. 4 applies equally to the embodiments of FIGS. 6 and 1l taking into account that the sizev of the opening of the embodiment illustrated in FIG. 7 will vary somewhat as to its required size to permit selective removal from the transverse opening becausev of the circular nature of the hole 60.

The bit and base block are intended, in each of the embodiments, to be used in substantially the same circumstances. That is to say, the base block is attached to the rotating member of a cutting machine that operates to propel the bit, point first, into a wall of the ore material or coal to be recovered. This operation is, of course, familiar to Ithose skilled in the art.

I claim a-s my invention:

1. A bit and mounting assembly, comprising:

(a) a bit including an elongate shank having a bearing face at the butt end and a cutting head at the other end,

(b) a base block including:

(l) a support means selectively receiving the shank,

and

(2) a bearing means operatively engaging the bearing face of the bit butt end,

(c) the bearing means being disposed in spaced relation, longitudinally of the shank, from the support means to partially define a transverse opening exposing the entire periphery of a portion of the shank at the butt end of the shank to facilitate access to the butt end and to facilitate dispersal of debris in the area of the bearing means,

(d) the bearing means including a replaceable bearing pad selectively removable from the transverse opening,

(e) retaining means holding the bearing pad in transverse alignment with the bearing face at the butt end of the shank,

(f) resilient means operatively acting on the bearing pad to engage the butt end of the shank and keep the shank free in the block for rot-ation.

2. A bit and mounting assembly as defined in claim 1,

in which:

(g) the retaining means limits movement of the pad in a direction, longitudinal of the shank, and

(h) lock means, disposed in the transverse opening, intercepts the path of the shank to inhibit outward movement of the shank away from the bearing means.

References Cited UNITED STATES PATENTS 2,564,307 8/ 1951 Keiser 308-166 2,708,609 5/ 1955 Triplett 308-159 3,397,012 8/1968 Krekeler 299-86 3,397,013 8/ 1968 Krekeler 299-86 ERNEST R. PURSER, Primary Examiner U.S. Cl. X.R. 299-92; 308-163 

